On Friday 27 February, Big Think partner PwC hosted its second global webcast focused on the question, ‘What would you do if you were not afraid?’ The webcast was part of ‘Aspire to Lead: The PwC Women’s...

Designers of the new federal system for sending emergency alerts to our cell phones devoted at lot attention to setting up the technical aspects, but not enough to figuring out what the messages should say....

Which scientific idea--offered up by experts such as Ray Kurzweil, Michio Kaku, Stephen Hawking and others--will impact our world the most? See our top contenders and vote for your favorite by sharing it on Facebook with your friends.

1. Biotechnology Will Stop Aging

Futurist Ray Kurzweil says the coming biotechnology revolution will allow us, in the next 15 to 20 years, to reprogram our genes to resist both aging and disease. By mid-century, we may all be kept healthy and young by billions of nanorobots inside of our bodies. According to Kurzweil, this breakthrough will open the gates of immortality.

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2. Adapting to Climate Change

"Climates always change" says Heidi Hammel, Senior Research Scientist at the Space Science Institute. "The question is, how are we going to adapt to climate change?" Geo-engineering? "I don’t think is the right way to do it," Hammel says. "How can we set up our population systems in cities so that they can react to a changing climate, you know, whether it’s getting hotter or colder. Mother nature will always throw surprises at us, and so here we are planning for this global warming. Well, 30 years ago we were planning for global cooling. It just goes to point out that we’re never really quite sure what we’re going to deal with. We need to be ready to deal."

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3. The Future Brain: Computers Will Read Our Thoughts

Technology is replicating and replacing functions long held in the brain. What does offloading your brain to technology mean for such vital human capacities as memory and creativity? Dr. Gary Small, Professor of Psychiatry and Aging, UCLA School of Medicine, says in the future you will wear a headband that will read your thoughts, so when you think a thought it will be translated wirelessly.

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4. Energy From Fusion in 20 Years

Sure, scientists always say that fusion is 20 years away, but this time theoretical physicist Michio Kaku says it’s for real. How significant would this be? Dr. Kaku tells Big Think "Fusion is the power of the sun, the possibility of using ordinary seawater to create unlimited amounts of energy due to thermonuclear reactions on the Planet Earth." Kaku adds that possessing such a vast amount of clean power in just two decades might not be one moment too soon, as the planet may very well be choking on greenhouse gases.

Watch the video and vote by sharing it with your friends on Facebook here.

5. Abandon Earth for Another Planet

Theoretical physicist Stephen Hawking says all we have to do is survive another two hundred years and the human race will be saved, because by that point human settlements in space will already be well-established. "I believe that the long-term future of the human race must be in space," Hawking tells Big Think.

Watch the video and vote by sharing it with your friends on Facebook here.